The present invention relates to coaxial joints, and particularly to joints for joining an inner cylindrical member to an outer cylindrical member while permitting rotary and/or linear movements between the two members.
Coaxial joints of the foregoing type commonly include a bushing disposed between the two cylindrical members, which bushing is non-rotatably received within the outer cylindrical member and includes a bore for rotatably receiving the inner cylindrical member. Such bushings are usually made of hard plastic material and are forcibly inserted into the outer cylindrical member so as to provide a firm, non-rotatable gripping thereof. The dimensions of the bore through the bushing are very critical in order to prevent any significant play when the inner cylindrical member is rotatably received within it. Therefore the conventional practice is to ream the final critical dimensions of the bore after the bushing has been forcibly introduced into the outer cylindrical member so as to compensate for any distortions of the bushing during this process. However, this reaming step adds substantially to the production costs of such a joint.
An object of the present invention is to provide a coaxial joint having a bushing of a construction such that the distortion of the bushing bore is substantially reduced or eliminated during the insertion of the bushing into the outer cylindrical member, so as to obviate the need for the usual reaming step.